Gardai investigating the fatal shooting of Christopher Warren arrested the man in his late 20s this morning. The first man arrested in connection with the incident - who is also in his late 20s - was released without charge earlier this morning.

A file will now be prepared for the Director of Public Prosecutions.

Warren, from St Teresa's Gardens in the capital's south inner city, became the 16th gun murder victim this year linked to criminal gangs and feuds.

The 35-year-old was dropped at the emergency unit of St James' Hospital at about 7pm on Friday night by a man in a car after being shot.

He was pronounced dead a short while later.

A Mercedes C-180 with a 01-D registration, believed to have been carrying Warren after he was shot, was found abandoned in Cork Street, less than a mile from the hospital.

The second man was arrested in the Dublin 8 area and is being detained under the provisions of section 50 of the Criminal Justice Act 2007 at Mountjoy Garda station.

Warren was a known criminal involved in burglary and had low-level links to crime and drugs gangs, believed to be factions from the Crumlin and Drimnagh areas.

A feud involving gangs from those areas has been going on for years and has claimed at least a dozen lives.

Warren's brother Paul was shot dead in a pub in Newmarket Square near the Liberties in 2004 in revenge for the murder of Joseph Rattigan, brother of crime gang leader Brian Rattigan.

Paul, 23, was not regarded as a major player on the crime scene at the time of his death.

Gardai have appealed for anyone with information on the latest murder to contact them.

They have also urged anyone who may have witnessed anything suspicious in the Cork Street area of the city or who may have seen the car that dropped Warren at the hospital to come forward.